Circuit board connector

ABSTRACT

A circuit board connector includes a main body portion, a first connecting portion for connection to a first circuit board, and a second connecting portion for connection to a second circuit board. The circuit board connector is obtained by cutting a conductive plate material provided with plating layers on front and back sides thereof, and thereafter forming the second connecting portion into a shape having an annular transverse cross section in such a manner that one of the plating layers forms an outer circumferential surface of the second connecting portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to circuit board connectors for connectingtwo circuit boards together.

2. Description of the Related Art

There are two types of circuit board connectors for connecting twocircuit boards each other; one type is a socket housing type that can bedismantled even after product assembling and the other is a type that isfixed by soldering during product assembling. Among the latter type,which is fixed by soldering, the one as described below is known. Thiscircuit board connector comprises, as illustrated in FIG. 13, a mainbody portion 2, a first connecting portion 1 for connection to a firstcircuit board, a second connecting portion 4 for connection to a secondcircuit board, and a lead portion 3 located between the secondconnecting portion 4 and the main body portion 2. The main body portion2 comprises an auxiliary connecting portion 21 formed from a portion ofthe main body portion 2, so that the connecting strength is improved bymaking connection with the first circuit board at two points, at thefirst connecting portion 1 and the auxiliary connecting portion 21.

As illustrated in FIG. 14, when connected to a circuit board of anelectronic apparatus such as a VTR, an electronic device 7 such as atuner is arranged uprightly in order to reduce the mounting area of thecircuit board. This necessitates the second connecting portion 4 to bedrawn out from a narrow surface of the circuit board that is arranged,in the electronic device, parallel to a wide surface in the electronicapparatus, and therefore, the first connecting portion 1 and theauxiliary connecting portion 21 are bent when connected to a circuitboard within the electronic device.

The outer shape of the above-described circuit board connector is, asillustrated in FIG. 15, formed by press cutting a single sheet ofconductive plate material 5 the front and back sides of which haveplating layers 6 of tin, nickel, or the like that have been formedthereon in advance. Thus, the transverse cross sections of the firstconnecting portion 1, the second connecting portion 4, and the auxiliaryconnecting portion 21 are formed to be rectangular.

However, cut surfaces 11 created by the press cutting are not providedwith the plating layers and therefore have lower solder wettability thanthose in which a plating layer is formed on the entire surfaces.Moreover, there is a certain length of time until an electronic deviceequipped with the circuit board connector is shipped to the user andmounted onto a circuit board of an electronic apparatus. During thattime, the second connecting portion of the circuit board connector isoxidized or rusted, and consequently a problem arises that solderwettability reduces.

In order to solve the foregoing problem, a method has been proposed inwhich re-plating is carried out for the circuit board connector afterthe press-cutting so that a plating layer is formed on the entiresurface.

Re-plating the terminal, however, adds an extra manufacturing step andalso increases cost. Moreover, the re-plating process usually adopts abarrel plating method, which involves putting samples to be plated intoa barrel-shaped container containing a plating solution and revolvingthe barrel-shaped container, and in the course of this process, theterminals deform or get tangled, reducing the yield and leading to afurther increase in cost. Furthermore, if a thin conductive platematerial is used for cost reduction, the mechanical strength of thecircuit board connector degrades, resulting in breakage during themanufacturing process and the mounting process to a circuit board, whichalso reduces the manufacturing yield.

The present invention has been accomplished to solve such problems, andit provides a circuit board connector with which good soldering ispossible even without performing a re-plating process.

SUMMARY OF THE INVENTION

A circuit board connector of the present invention comprises a main bodyportion, a first connecting portion for connection to a first circuitboard, and a second connecting portion for connection to a secondcircuit board; and

the circuit board connector is obtained by cutting a conductive platematerial provided with plating layers on front and back sides thereof,and thereafter forming the second connecting portion so as to have anannular transverse cross section in such a manner that one of theplating layers forms an outer circumferential surface of the secondconnecting portion.

In a circuit board connector of the present invention, cut surfaces atboth edges of the second connecting portion oppose each other inaddition to the foregoing configuration.

Moreover, in a circuit board connector of the present invention, a gapis provided between the cut surfaces at both edges of the secondconnecting portion that oppose each other.

In addition, a circuit board connector of the present invention is suchthat a circuit board connector comprising a first connecting portion forconnection to a first circuit board and a second connecting portionconnected to a second circuit board, wherein:

the circuit board connector is obtained by cutting a conductive platematerial provided with plating layers on front and back sides, andthereafter forming the second connecting portion so as to have anannular transverse cross section and bending the second connectingportion so that cut surfaces are located inside the annularcross-sectional shape.

By allowing one of the plating layers of the second connecting portionto form the outer circumferential surface, solder wettability can beimproved without performing an extra plating process. Moreover, byprocessing the second connecting portion so as to have an annular crosssection, the mechanical strength of the circuit board connector can beimproved, and therefore, a conductive plate material that is thinnerthan that in conventional products can be used; thereby, cost can bereduced.

Since the cut surfaces at both edges of the second connecting portionoppose each other, the cut surfaces, which are not plated, are notpresent in the outer circumferential surface; thus, solder wettabilitycan be improved.

Moreover, by providing a gap between the cut surfaces at both edges ofthe second connecting portion, solder comes into the gap by capillaryaction, making it possible to improve solder wettability.

By forming the second connecting portion so as to have an annulartransverse cross section and bending the second connecting portion sothat the cut surfaces are located inside the annular shape, the cutsurfaces that are not plated are kept away from the outercircumferential surface that is to be soldered. Therefore, rusting thatdevelops on the cut surfaces over time does not easily reach the outercircumferential surface, making it possible to conduct good soldering.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a manufacture view and a side view of a circuit boardconnector according to an embodiment of the present invention;

FIG. 2 shows an enlarged view of a portion A in FIG. 1 and a top viewthereof;

FIG. 3 is a cross-sectional view taken along the line B—B in FIG. 2;

FIG. 4 is a cross-sectional view taken along the line D—D in FIG. 2;

FIG. 5 shows a front elevational view of a circuit board connectoraccording to a second embodiment and a top view thereof;

FIG. 6 is a cross-sectional view taken along the line B—B in FIG. 5;

FIG. 7 is a cross-sectional view taken along the line D—D in FIG. 5;

FIG. 8 is a cross-sectional view illustrating process steps of a secondconnecting portion in a third embodiment;

FIG. 9 is a cross-sectional view illustrating a second connectingportion in another embodiment;

FIG. 10 is a cross-sectional view illustrating the state in which thesecond connecting portion of the first embodiment is inserted into aconnecting socket of a circuit board;

FIG. 11 is a cross-sectional view illustrating the state in which thesecond connecting portion of a conventional product is inserted into aconnecting socket of a circuit board;

FIGS. 12A, 12B and 12C are transverse cross-sectional views of a secondconnecting portion in another embodiment of the present invention;

FIG. 13 is a front elevational view and a side view of a conventionalpress-formed type terminal;

FIG. 14 is a view illustrating an arrangement of a first circuit boardarranged on a second circuit board; and

FIG. 15 is a perspective view showing a conventional conductive platematerial (a) before a step of press-cutting and (b) after the step ofpress-cutting.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

A circuit board connector according to the present invention comprises amain body portion 2, a first connecting portion 1 for connection to afirst circuit board in an electronic device, a second connecting portion4 for connection to a second circuit board in an electronic apparatus, alead portion 3 between the second connecting portion 4 and the main bodyportion 2, and an auxiliary connecting portion 21 formed from a part ofthe main body portion.

The circuit board connector of the present invention is formed bycutting a conductive plate material provided with plating layers on itsfront and back sides, and thereafter forming the second connectingportion into a shape having an annular cross section so that one of theplating layers forms the outer circumferential surface of the secondconnecting portion.

Herein, the term “annular shape” used in the present invention isintended to describe the shape that forms an inner hollow 16, and theouter shape is not particularly limited. Examples of annularcross-sectional shapes that may be adopted include, as illustrated inFIGS. 12A–12C, a circular shape (FIG. 12A), an elliptical shape (FIG.12B), and an elongated elliptical shape (FIG. 12C). The outer shape maybe changed as appropriate depending on the shape of the terminal socketsof the second connecting circuit.

There are no particular limitations on the plating layers used for theconductive plate material in the present invention as long as theirmaterials have high electrical conductivity, and usable materialsinclude gold, silver, copper, nickel, and palladium. In the followingembodiments, a tin-plated conductive plate material was used.

The circuit board connector according to the present invention isfabricated as follows. As illustrated in FIG. 1, the outer shape of thecircuit board connector was formed by press-cutting a conductive platematerial 13, which was a steel plate or the like the front and backsides of which are provided with tin plating layers, so that theinterval (P) between the terminals was 4 mm.

Thereafter, as illustrated in FIG. 3, the cut surfaces 11 of the secondconnecting portion 4 were opposed so that one of the plating layersforms the outer circumferential surface of the second connectingportion, and thus the terminal was processed to have an annular crosssection. Further, as illustrated in FIG. 4, the cut surfaces 11 of thelead portion 3 were opposed and the lead portion was processed to havean O-shaped transverse cross section, and thus, a circuit boardconnector as shown in FIG. 2 was completed.

In addition, because the second connecting portion 4 needed to be drawnout in a vertical direction from the circuit board arranged horizontallyin the electronic device, the first connecting portion 1 and theauxiliary connecting portion 21 of the terminal were subjected to abending process such as to be bent at right angles with respect to thesecond connecting portion.

FIG. 5 is a front elevational view and a top view illustrating a secondembodiment of the circuit board connector according to the presentinvention. The second circuit board connector was obtained as follows:the outer shape of the circuit board connector was formed usingpress-cutting as in the first embodiment; thereafter, as illustrated inFIG. 6, a gap was provided such that cut surfaces 11 at both edges ofthe second connecting portion do not come into close contact with eachother and that its cross section has a shape so that the plating layerforms the outer circumferential surface of the second connectingportion. Thereafter, the cut surface of the lead portion was processedinto a C-shaped transverse cross section as illustrated in FIG. 7 forreinforcement, and thus a circuit board connector was completed.

A circuit board connector of a third embodiment according to the presentinvention was obtained as follows. The outer shape was formed by presscutting a conductive plate material as in the first embodiment.Thereafter, the second connecting portion was processed as illustratedin FIG. 8 in the following manner. First, both ends of the secondconnecting portion near cut surfaces were bent at an acute angle, andthereafter, the second connecting portion was gradually processedthrough several manufacturing steps so as to have an annular crosssection, so that the cut surfaces were brought inside the annular shape.Thereafter, the cut surface of the lead portion was processed into aC-shaped transverse cross section as illustrated in FIG. 7 forreinforcement, and thus a circuit board connector was completed.

In the above-described embodiments of the present invention, when thecircuit board connector is in use, the first connecting portion 1 andthe auxiliary connecting portion 21 are fixed onto the first circuitboard by soldering and the second connecting portion 4 is fixed onto thesecond circuit board by soldering.

With the above-described configurations, the cut surfaces 11 of theconductive plate material 13 after the press-cutting are not present onthe outer circumferential surface of the second connecting portion 4 ofthe terminal that is to be soldered, and therefore, solder wettabilitycan be improved over conventional products.

Moreover, the terminal of the second embodiment is provided with a smallgap between the cut surfaces 11 at both edges of the second connectingportion 4; therefore, solder comes into the gap by capillary action,making it possible to improve solder wettability.

Furthermore, the terminal of the third embodiment has the cut surfaces11 of the second connecting portion 4 that are bent so as to come insidethe annular shape, making it possible to keep the cut surfaces 11 thatare not plated away from the outer circumferential surface that is to besoldered. Consequently, even when rusting develops on the cut surfaces11 over time and corrosion due to the rusting reaches the platedsurface, the rust does not easily reach the outer circumferentialsurface of the second connecting portion, and therefore, it is possibleto conduct good soldering. To obtain this effect, it is sufficient thatthe cut surfaces come inside the annular shape, and for example, thesame effect can be attained with a shape as illustrated in FIG. 9, inwhich the cut surfaces of the portion to be soldered of the secondconnecting portion are processed to be rounded to come inside theannular shape.

As illustrated in FIG. 11, when a conventional circuit board connectorin which the portion to be soldered to a circuit board is rectangular isinserted into a circular terminal connecting socket 14 of a circuitboard, the gap between the portion to be soldered and the circularterminal connecting socket is not uniform, producing distant portions;therefore, the connecting strength is weak. In contrast, the secondconnecting portion 4 of the terminal of the present invention is shapedto have an annular cross section, as illustrated in FIG. 10; therefore,the gap 15 to the circular terminal connecting socket 14 is uniform,making it possible to improve the connecting strength.

In addition, the terminal in which the second connecting portion 4 isformed to have an annular transverse cross section as in the embodimentscan improve the mechanical strength of the second connecting portionover the conventional product that is not subjected to a bendingprocess. For this reason, it is possible to use a conductive materialthat is thinner than that in conventional products, leading to costreduction. Furthermore, the mechanical strength of the terminal can befurther improved by applying a bending process an O-shaped or C-shapedcross section or the like to the lead portion, as in the embodiments.

The embodiments used one having an auxiliary connecting portion formedfrom a portion of the main body portion and the first connecting portionand the auxiliary connecting portion was bending-processed at rightangles with respect to the second connecting portion; however, thenumber and shape of the first connecting portion(s) are not limited tothe foregoing and may be varied within the scope of the claims.

When the first connecting portion of a terminal of the present inventionas described above is used for an electronic device that is arrangeduprightly, such as a tuner, it is possible to make effective use of thespace on the circuit and to prevent occurrences of rusting and oxidationof the second connecting portion of the terminal. Consequently, goodsoldering can be conducted even when a certain time has elapsed aftershipment of the electronic device until mounting of the electronicdevice onto an electronic apparatus.

INDUSTRIAL APPLICABILITY

With the circuit board connector of the present invention, goodsoldering is possible since a plating layer is formed on the outercircumferential surface of the second connecting portion. Moreover, itis possible to use a conductive plate material that is thinner than wasconventionally possible because the mechanical strength of the secondconnecting portion is improved. Therefore, cost reduction can beachieved.

1. A circuit board connector formed by cutting a conductive platematerial provided with plating layers on front and back sides thereof,said circuit board connector comprising: a main body portion; a firstconnecting portion bent at a right angle to said main body portion forconnection to a first circuit board; a second connecting portion forconnection to a terminal connecting socket of a second circuit board,the second connecting portion being positioned in the terminalconnecting socket; and an auxiliary connecting portion formed from aportion of the main body portion and bent so as to be parallel to saidfirst connecting portion, thereby leaving an opening in the main bodyportion, wherein the second connecting portion of the circuit boardconnector is formed into a shape having an annular transverse crosssection in such a manner that cut surfaces at both edges of the secondconnecting portion oppose each other, so that one of the plating layersmay form an outer circumferential surface of the second connectingportion and be connected to the terminal connecting socket, and whereineach of said plating layers is formed from one of gold, silver, copper,nickel, palladium and tin.
 2. The circuit board connector according toclaim 1, wherein a gap is provided between the cut surfaces at bothedges of the second connecting portion that oppose each other.
 3. Thecircuit board connector according to claim 2, wherein a lead portion isprovided between the main portion and the second connecting portion, andthe lead portion is subjected to a bending process for reinforcement. 4.The circuit board connector according to claim 3, wherein in the bendingprocess the lead portion is formed to have an O-shaped or C-shapedtransverse cross section.
 5. A method of manufacturing an electronicapparatus, comprising: mounting an electronic device furnished with afirst circuit board to which the first connecting portion of the circuitboard connector according to claim 1 is connected, uprightly onto asecond circuit substrate arranged in the electronic apparatus.
 6. Acircuit board connector, comprising a first connecting portion bent at aright angle to a main body portion of said connector for connection to afirst circuit board and a second connecting portion connected to asecond circuit board, wherein the circuit board connector is obtained bycutting a conductive plate material provided with plating layers onfront and back sides, and thereafter forming the second connectingportion so as to have an annular transverse cross section and bendingthe second connecting portion so that cut surfaces are located insidethe annular cross-sectional shape, wherein an auxiliary connectingportion is formed from a portion of said main body portion and is bentso as to be parallel to said first connecting portion, and wherein eachof said plating layers is formed from one of gold, silver, copper,nickel, palladium and tin.
 7. The circuit board connector according toclaim 6, wherein the circuit board connector comprises a lead portionbetween the main body portion and the second connecting portion, and thelead portion is subjected to a bending process.
 8. The circuit boardconnector according to claim 7, wherein in the bending process the leadportion is formed to have an O-shaped or C-shaped transverse crosssection.
 9. A method of manufacturing an electronic apparatus,comprising: mounting an electronic device furnished with a first circuitboard to which the first connecting portion of the circuit boardconnector according to claim 6 is connected, uprightly onto a secondcircuit substrate arranged in the electronic apparatus.